Adds the concept of an AssetCredit to pkg/kubecost/asset

pkg/kubecost/asset.go

@@ -184,6 +184,71 @@ const (
 	SharedAssetType
 )
 
+// AssetCredit represents credit applied to the cost of an Asset
+type AssetCredit struct {
+	Amount float64
+	Name   string
+	Type   string
+}
+
+// Clone returns a copy of AssetCredit
+func (ac AssetCredit) Clone() AssetCredit {
+	return AssetCredit{
+		Amount: ac.Amount,
+		Name:   ac.Name,
+		Type:   ac.Type,
+	}
+}
+
+// Equal returns true if the AssetCredits are equal. False otherwise.
+func (ac AssetCredit) Equal(that AssetCredit) bool {
+	return (ac.Amount == that.Amount &&
+		ac.Name == that.Name &&
+		ac.Type == that.Type)
+}
+
+// AssetCredits is a slice of `AssetCredit`
+type AssetCredits []AssetCredit
+
+// Clone returns a deep copy of the AssetCredits
+func (acs AssetCredits) Clone() AssetCredits {
+	cloneSlice := make(AssetCredits, len(acs))
+	for _, credit := range acs {
+		cloneSlice = append(cloneSlice, credit.Clone())
+	}
+	return cloneSlice
+}
+
+// Equal returns true if the given AssetCredits are equal. False otherwise.
+func (acs AssetCredits) Equal(that AssetCredits) bool {
+	if len(acs) != len(that) {
+		return false
+	}
+	for i := range acs {
+		if !acs[i].Equal(that[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Map executes function iteritee on each element of the slice, and returns a slice of the results
+func (acs AssetCredits) Map(iteritee func(int, AssetCredit) AssetCredit) AssetCredits {
+	mappedCredits := AssetCredits{}
+	for index, credit := range acs {
+		mappedCredit := iteritee(index, credit)
+		mappedCredits = append(mappedCredits, mappedCredit)
+	}
+	return mappedCredits
+}
+
+// Scale scales all credit values by some supplied factor
+func (acs AssetCredits) Scale(scaleFactor float64) {
+	for _, credit := range acs {
+		credit.Amount *= scaleFactor
+	}
+}
+
 // ParseAssetType attempts to parse the given string into an AssetType
 func ParseAssetType(text string) (AssetType, error) {
 	switch strings.TrimSpace(strings.ToLower(text)) {
@@ -424,6 +489,7 @@ type Cloud struct {
 	window     Window
 	adjustment float64
 	Cost       float64
+	Credits    AssetCredits
 }
 
 // NewCloud returns a new Cloud Asset
@@ -477,6 +543,15 @@ func (ca *Cloud) SetAdjustment(adj float64) {
 	ca.adjustment = adj
 }
 
+// TotalCreditAmount returns the total amount of all credits applied to the asset
+func (ca *Cloud) TotalCreditAmount() float64 {
+	total := 0.0
+	for _, credit := range ca.Credits {
+		total += credit.Amount
+	}
+	return total
+}
+
 // TotalCost returns the Asset's total cost
 func (ca *Cloud) TotalCost() float64 {
 	return ca.Cost + ca.adjustment
@@ -581,6 +656,7 @@ func (ca *Cloud) add(that *Cloud) {
 	ca.SetLabels(labels)
 	ca.adjustment += that.adjustment
 	ca.Cost += that.Cost
+	ca.Credits = append(ca.Credits, that.Credits...)
 }
 
 // Clone returns a cloned instance of the Asset
@@ -593,6 +669,7 @@ func (ca *Cloud) Clone() Asset {
 		window:     ca.window.Clone(),
 		adjustment: ca.adjustment,
 		Cost:       ca.Cost,
+		Credits:    ca.Credits.Clone(),
 	}
 }
 
@@ -627,6 +704,9 @@ func (ca *Cloud) Equal(a Asset) bool {
 	if ca.Cost != that.Cost {
 		return false
 	}
+	if !ca.Credits.Equal(that.Credits) {
+		return false
+	}
 
 	return true
 }
@@ -637,6 +717,7 @@ func (ca *Cloud) MarshalJSON() ([]byte, error) {
 	jsonEncodeString(buffer, "type", ca.Type().String(), ",")
 	jsonEncode(buffer, "properties", ca.Properties(), ",")
 	jsonEncode(buffer, "labels", ca.Labels(), ",")
+	jsonEncode(buffer, "credits", ca.Credits, ",")
 	jsonEncodeString(buffer, "window", ca.Window().String(), ",")
 	jsonEncodeString(buffer, "start", ca.Start().Format(timeFmt), ",")
 	jsonEncodeString(buffer, "end", ca.End().Format(timeFmt), ",")